VBA to repeat macro x times

Maybe:

Sub cossie2kaazz()
Dim i As Long
Dim z As Long
z = 21
Do Until z = 0
For i = Range("A" & Rows.Count).End(3)(1).Row To 2 Step -1
    If Range("D" & i) = "Task 1" Then
        Range("D" & i + 1).EntireRow.Insert
        Rows(i + 1).Value = Rows(i).Value
        Cells(i + 1, 4).Value = "Task 1"
        x = i + 2
        Cells(i + 1, 5).Value = "=R[-1]C+1"
        Cells(i + 1, 6).Value = "=R[-1]C+1"
    End If
Next i
z = z - 1
Loop
End Sub